1G/2.5G/5G/10G Multirate Ethernet PHY Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs

ID 813667
Date 7/08/2024
Public
Document Table of Contents

5.1. Clock Signals

Table 15.  Clock Signals
Signal Name Direction Width Description PHY Configurations
tx_clkout Output 1 GMII TX clock, derived from tx_pll_refclk. Provides 156.25 MHz timing reference for 2.5G; 62.5 MHz for 1G, 100M, and 10M.
  • 2.5G (MGBASE-T)
  • 1G/2.5G (MGBASE-T)
  • 10M/100M/1G/2.5G (MGBASE-T)
rx_clkout Output 1 GMII RX clock, derived from tx_pll_refclk. Provides 156.25 MHz timing reference for 2.5G; 62.5 MHz for 1G, 100M, and 10M.

This clock is internally connected to tx_clkout with rate match FIFO.

  • 2.5G (MGBASE-T)
  • 1G/2.5G (MGBASE-T)
  • 10M/100M/1G/2.5G (MGBASE-T)
csr_clk Input 1 Clock for the control and status interface. Altera recommends 100 MHz for this clock. All
xgmii_tx_coreclkin Input 1 TX clock for XGMII logic before phase compensation FIFO.

Provides a 312.5 MHz timing reference for the 10M/100M/1G/2.5G/5G/10G (USXGMII) mode.

10M/100M/1G/2.5G/5G/10G (USXGMII)
xgmii_rx_coreclkin Input 1 RX clock for XGMII logic after rate matcher.

Provides a 312.5 MHz timing reference for the 10M/100M/1G/2.5G/5G/10G (USXGMII) mode.

10M/100M/1G/2.5G/5G/10G (USXGMII)

tx_pll_refclk_p

Input 1 Reference clock for each of the TX PLL.
  • MGBASET supports 156.25/312.5 MHz
  • NBASET supports 156.25/312.5/322.2656 MHz

rx_cdr_refclk_p

Input 1

Reference clock for the RX CDR.

MGBASE-T only
i_system_pll_clk Input 1 To be connected to the GTS System PLL Clock Intel® FPGA IP PLL output. All
i_system_pll_lock Input 1 System PLL locked signal. All
latency_measure_clk Input 1 Sampling clock for measuring the latency of the 16-bit GMII datapath. This clock operates at 80 MHz ± 100 ppm and is available only when the IEEE 1588 feature is enabled.
  • 2.5G
  • 1G/2.5G (MGBASE-T) with IEEE 1588 feature
latency_sclk Input 1 Sampling clock for measuring the latency of the transceiver AIB datapath. The clock period is 4.375 ns for 2.5G and 1G/2.5G (MGBASE-T), 6.5 ns for 10M/100M/1G/2.5G/5G/10G (USXGMII) It is available only when the IEEE 1588 feature is enabled. 10M/100M/1G/2.5G/5G/10G (USXGMII) with IEEE 1588
rx_pma_clkout Output 1 Recovered clock from CDR, operates at the following frequency:
10M/100M/1G/2.5G/5G/10G (USXGMII) speed mode:
  • All speeds: 156.25 MHz
Other speed modes:
  • 1G: 125 MHz
  • 2.5G: 312.5 MHz
  • 1G/2.5G (MGBASE-T)
  • 10M/100M/1G/2.5G (MGBASE-T)
  • 10M/100M/1G/2.5G/5G/10G (USXGMII)
i_pma_cu_clk Input 1 PMA Control Unit clock, one per GTS bank for each side of the device. This clock port must be connected from the GTS Reset Sequencer Intel® FPGA IP. The clock frequency is 250 MHz.
  • 1G/2.5G (MGBASE-T)
  • 10M/100M/1G/2.5G (MGBASE-T)
  • 10M/100M/1G/2.5G/5G/10G (USXGMII)
o_clk_pll Output 1 Clock derived from the System PLL associated with the Ethernet Port. The frequency is the system PLL frequency divided by 2. It should be used in the user logic to generate xgmii_*_coreclkin for a synchronous user application. 10M/100M/1G/2.5G/5G/10G (USXGMII)
i_clk_pll Input 1 This clock signal is unused. Tie this signal to ground. USXGMII
gmii8b_tx_clkout Output 1 GMII TX clock, derived from tx_pll_refclk. Provides 312.5 MHz timing reference for 2.5G; 125 MHz for 1G, 100M, and 10M. GMII/MII transmit clock to HPS
gmii8b_rx_clkout Output 1 GMII RX clock, derived from tx_pll_refclk. Provides 312.5 MHz timing reference for 2.5G; 125 MHz for 1G, 100M, and 10M. GMII/MII receive clock to HPS
gmii8b_tx_clkin Input 1 TX out clock. GMII/MII transmit clock from HPS